A variety of research projects within the proposed Core-Center employ human subjects. However, all currently operate independently, with rare interaction between them. The reason is that no structures exist to facilitate our collective goals. There is no centralized database of subjects available and no personnel to coordinate our needs across studies. These shortcomings will be solved by the Human Subjects Core. We will build upon pre-existing mechanisms from our individual grants currently in place but uncoordinated. The Core will provide several key services. First, the Core will coordinate recruitment and screening of human subjects across research projects. This includes identifying subjects and obtaining informed consent, followed by basic medial and sensorimotor/neurologic exams, and cognitive screening relevant to the populations targeted by Core studies. Populations now under study include normal subjects across a broad range of ages, adults across ages with acquired hearing loss, elderly subjects with Alzheimer's disease, and subjects with unilateral and bilateral peripheral vestibular loss. Second, the Core will coordinate scheduling and tracking across projects in order to maximize efficiency and convenience for subjects, investigators and staff. Further, the use of common subjects across studies supplies novel and paired observations that enhance productivity and stimulate new and collaborative research. Third, the Core will implement and maintain a powerful database that will provide protected access to data and analytic tools for investigators and staff. This central service will promote new studies while making existing ones more efficient. Finally, Core services will include the coordination of protocol approvals, staff credentialing, and record keeping required of all human studies. The above services and tasks are made exceedingly efficient by a centralized structure orchestrated by a trained Coordinator. The benefits gained will unload time and effort for faculty and staff to pursue more directly relevant research goals, and will simultaneously catalyze new projects and collaborations.